problem

  File "/home/inksci/ai-ink/ppo-dice-master/baselines/common/atari_wrappers.py", line 7, in <module>

    import cv2
ImportError: /opt/ros/kinetic/lib/python2.7/dist-packages/cv2.so: undefined symbol: PyCObject_Type

solution

    
import cv2

to

import sys
if '/opt/ros/kinetic/lib/python2.7/dist-packages' in sys.path:
    sys.path.remove('/opt/ros/kinetic/lib/python2.7/dist-packages')     
import cv2